Bufonidae is the family of the true toads, members of the order Anura (frogs and toads). They are the only family of anurans all members of which are known as "toads." The bufonids now comprise more than 35 genera.
True toads are widespread and occur natively on every continent except Australia and Antarctica, inhabiting a variety of environments, from arid areas to rainforest. Most lay eggs in paired strings that hatch into tadpoles, although, in the genus Nectophrynoides the eggs hatch directly into miniature toads.
True toads are toothless and generally warty in appearance. They have a pair of parotoid glands on the back of their heads. These glands contain an alkaloid poison which the toads excrete when stressed. The poison in the glands contains a number of toxins causing different effects. Bufotoxin is a general term. Different animals contain significantly different substances and proportions of substances. Some, like the cane toad Bufo marinus, are more toxic than others. Some "psychoactive toads," such as the Colorado River Toad Bufo alvaris, have been used recreationally for the effects of the bufotoxin.
Male toads possess a Bidder's organ. Under the right conditions, the organ becomes an active ovary and the toad, in effect, becomes female.
Source: en.wikipedia.org/wiki/True_toad - 22.11.2011
In spring the True Toads again and again frequent the same waters for spawning.